1. Field of the Invention
The present invention relates in general to a quickly and safely maintained sand-filtering device.
2. Description of the Related Art
Referring to FIG. 1, a conventional sand-filtering device 2 for a sandblaster has a housing provided with an air intake 10 and an air outlet 12. The air intake 10 is connected to a sandblast machine 1. In the housing are provided a top plate 21, a bottom plate 22, a plurality of springs 23 and filtering sleeves 24. The top plate 21 and the bottom plate 22 are spaced apart to form a space 14, in which the filtering sleeves 24 are disposed. The filtering sleeves 24 are flexible and contain the springs 23. The spring 23 have hooks at their ends to hang the filtering sleeves 24 on the top plate 21. Further referring to FIG. 2, the bottom plate 22 is provided with a plurality of hollow cylinders 221. The bottom ends of the filtering sleeves 24 are tied to the hollow cylinders 221 via laces.
The sand-filtering device 2 is arranged at the tail of the sandblast machine 1 to receive the used sands during the blasting process. The used sands enter the chamber 20 of the sand-filtering device 2. The air pump 27 pumps air in the sand-filtering device 2 out to carry the used sands upward so that the used sands adhere to the inner walls of the filtering sleeves 24. When the blasting process is finished, the air pump 27 stops. An oscillator 25 starts to horizontally swing the top plate 21 and then swing the springs 23. The springs 23 repeatedly hit the flexible filtering sleeves 24 from side to side so that the sands on the inner walls of the filtering sleeves 24 fall. A collecting bag 3 is provided under the filtering sleeves 24 to collect the sands.
However, repeated hits cannot separate all the sands from the filtering sleeves 24. A part of sands still adhere to the inner walls of the filtering sleeves 24. After months, sands accumulate so that the filtering sleeves 24 fail and need to be replaced with new ones. The top plate 21 and the bottom plate 22 are made of metal and permanently fixed in the sand-filtering device 2. Therefore, the top and bottom plates 21, 22 are not replaced. The life span of the filtering sleeve 24 depends on the amount of the used sand. A large amount of sands results in frequent replacement of filtering sleeves.
The filtering sleeve 24 is replaced in accordance with the following manner: The lace 26 is loosened and taken away from the filtering sleeve 24. Then, the filtering sleeve 24 is lifted to separate the hook of the spring 23 from the top plate 21. Then, the whole filtering sleeve 24 is thrown away. When the lace 26 is detached from the filtering sleeve 24, a large quantity of sands falls out and floats in the air. The fall-out sands are harmful to worker""s health and the environment.
An object of the present invention is to provide a sand-filtering device of quick and safe maintenance for a sandblaster that solves the above-mentioned problems.
The sand-filtering device of the present invention includes a housing, a supporting plate, at least one filtering sleeve, a division module and an air pump. The housing is connected to the sandblast machine to receive the sands. The supporting plate is detachably mounted in the housing. The filtering sleeve is hung on the supporting plate. The division module is detachably mounted in the housing. The division module has at least one passage connected to the filtering sleeve. The air pump pumps the sands through the passage into the filtering sleeve so that the sands are filtered by the filtering sleeve. To replace the filtering sleeve, the supporting plate and the division module are detached from the housing and directly thrown away together with the filtering sleeve. That is fast, efficient and safe.